Species of Laboulbenia on ground beetles (Coleoptera, Carabidae) collected in a mountain rainforest in Western Panama are described and illustrated. A new species of Laboulbenia on carabids of the genus Platynus (Platynini) in Panama is proposed. It differs from the other species of Laboulbenia mainly by curved thalli and longitudinally twisted wall cells of the perithecia with lips oriented towards strongly branched appendages. L. decipiens, L. pseudomasei, L. subpunctata, and L. tenera are newly recorded for Panama. Only one species collected during the survey is already known for Panama, L. flagellata.